Refrigerator

ABSTRACT

A refrigerator is provided that has an interior that is surrounded by an inner shell, the interior for storing refrigerated or frozen products. The refrigerator includes a control system that has a cold generator. A temperature sensor is arranged in the interior, wherein the temperature sensor is connected to the control system. A screen prevents contact between the temperature sensor and the refrigerated or frozen products.

The invention relates to a refrigeration appliance as claimed in the preamble of claim 1.

Refrigeration appliances are usually provided with a refrigerant circuit comprising a compressor, a condenser, and an evaporator. In order to be able to cool the interior of the refrigeration appliance accordingly, the compressor is put into operation and the refrigerant is compressed. In the condenser the refrigerant heated up by the compression cools down and in this process changes to the liquid state. The refrigerant expands in the evaporator, in this process changes to the gaseous state and cools down significantly. In this way the refrigerant can absorb heat from the interior and discharge said heat in an outward direction via the condenser. In order to regulate the refrigerant circuit, provision is made for a control system, which is connected to a temperature sensor. Usually the temperature of the refrigerant in the evaporator is measured. For this purpose, a temperature sensor is arranged on the evaporator.

It has proven that refrigeration appliances thus regulated, in particular in the fully loaded state, are not regulated in the correct manner. It has been shown that the interior is cooled down to a value, which is below the set value. It was determined that this incorrect regulating behavior occurs precisely when the stored refrigerated or frozen products make contact with the temperature sensor. In this case, the temperature sensor not only records the temperature of the refrigerant in the evaporator, but is at the same time influenced by the temperature of the refrigerated or frozen products. Because said temperature is always lower than the temperature of the refrigerant, this results in longer running times of the compressor and for this reason in a higher energy consumption.

The object underlying the present invention is thus to improve the regulating behavior of a refrigeration appliance and to reduce the energy consumption.

This object is achieved in accordance with the invention by means of a refrigeration appliance with the features of claim 1. The screen, which prevents contact between the temperature sensor and the refrigerated and/or frozen products ensures that even in the case of a fully loaded refrigeration appliance, only the temperature of the refrigerant in the evaporator is measured. Direct contact between the temperature sensor and the stored refrigerated and/or frozen products is prevented in a reliable way.

In the case of the invention it is irrelevant which type of refrigeration unit is used in the refrigeration appliance. The invention can also be used in this way for a refrigeration appliance that uses a Peltier element. However the invention is preferably used for a refrigeration appliance with an evaporator.

In a preferred exemplary embodiment of the invention, the evaporator itself forms the screen for the temperature sensor. For refrigeration appliances in which the evaporator is mounted on the inner shell, the temperature sensor is preferably fixed to the side of the evaporator, which faces away from the refrigerated and/or frozen products. However, it is also possible for the temperature sensor to be fixed to the inner shell in such a way that it is only a small distance from the evaporator. In both cases the evaporator itself functions as a screen and prevents the refrigerated and/or frozen products coming into contact with the temperature sensor.

In an exemplary embodiment of the invention, the inside of the inner shell of the refrigeration appliance is provided with a groove. Said groove is shielded by means of the evaporator and accommodates the temperature sensor. In the case of this embodiment the temperature sensor is thermally shielded from three sides by the inner shell and the insulating foam surrounding said inner shell. The evaporator is located a short distance away on the only open side of the groove. In this way a screen is obtained against the stored refrigerated and/or frozen products and at the same time it is ensured that the temperature of the refrigerant is measured with a high level of accuracy.

The temperature sensor is advantageously arranged in a protective tube. The protective tube produces reproducible measurement conditions. If the evaporator rests closely against the protective tube, there is always the same distance between the evaporator and the temperature sensor. Likewise the protective tube prevents damage to the temperature sensor. This applies to possible damage to the temperature sensor during assembly but also in the case of a fully loaded refrigeration appliance when the refrigerated and/or frozen products press against the evaporator. In this case the evaporator could damage the temperature sensor due to the pressure on said temperature sensor. Such damage is also prevented by the protective tube. The protective tube can be mounted permanently in the groove of the inner shell. However, provision can also be made for a protective tube, which is permanently connected to the evaporator. Such a protective tube could for example be provided with clip or latching means in order to be fixed to the evaporator tube in this way. For a corresponding embodiment of the protective tube a plastic would be suitable, which would also not lose its elasticity in extreme cold. However the protective tube could also be made of metal and be fixed to the evaporator by means of a soldered joint or a welded joint.

In order to simplify the assembly of the temperature sensor, the protective tube can be provided with an insertion funnel The insertion funnel also reduces the risk of damage to the temperature sensor during assembly.

Further details and advantages of the invention are found in the subclaims in conjunction with the description of exemplary embodiments described in more detail with reference to the drawing, in which;

FIG. 1 shows a detailed section through a refrigeration appliance in accordance with the invention;

FIG. 2 shows a sensor support mounted on the evaporator using clamps; and

FIG. 3 shows a sensor tube with an insertion funnel fixed to the evaporator tube.

The refrigeration appliance shown in FIG. 1 comprises an inner shell 1, which surrounds the interior for accommodating the refrigerated and/or frozen products. In order not to allow the transfer of heat from the environment to the interior, the inner shell 1 is enveloped by the insulating foam 2.

The inner shell 1 has already been equipped with supports for the wire tubular evaporator 3. In order to be able to mount the wire tubular evaporator 3 in a definite position, the holders 6 are provided to press the wire tubular evaporator 3 into its intended position. The wire tubular evaporator 3 consists of an evaporator tube 4 which is bent in a looped manner and which is stabilized by way of the transverse wires 5. The transverse wires 5 are welded to the evaporator tube 4 on its upper and lower faces.

Provision is made for a groove 7 in the cover part of the inner shell 1. The groove 7 is intended to accommodate a protective tube 8. The temperature sensor 9 is housed in the protective tube 8.

The protective tube 8 is in direct contact with the transverse wires 5. The transverse wires 5 are thermally coupled to the evaporator tube 4 by way of weld spots so that they have practically the same temperature as the refrigerant. The distance between the temperature sensor 9 and the transverse wires 5 is predefined by the thickness of the protective tube 8. Direct contact between the temperature sensor 9 and the stored refrigerated and/or frozen products is prevented because the wire tubular evaporator 3 itself functions as a screen. As a result, the same measurement conditions are always present for the regulation of the compressor (not shown here). The stored refrigerated and/or frozen products do not falsify the measurement.

FIG. 2 shows a further exemplary embodiment of the invention. In this case the sensor support 11 is fixed directly to the evaporator tube 4 by means of a clamp 12. The clamp 12 has contact tongues 10, which have a certain amount of pre-tension so that a form-fit is generated between the clamp 12 and the evaporator tube 4. In this process the sensor support 11 is pressed directly onto the evaporator tube 4.

The clamp 12 is preferably embodied as a single piece with the sensor support 11 and made of plastic. An appropriate shaped part can be extruded very cost-effectively or it can be produced as an injection molded part. With this exemplary embodiment too the temperature sensor inserted into the sensor support 11 is shielded from the stored refrigerated and/or frozen products by the wire tubular evaporator. Contact is prevented so that the same measurement conditions are always present here too.

The sensor tube 13 shown in FIG. 3 has an insertion funnel 14. Said insertion funnel 14 facilitates the assembly of the temperature sensor and prevents damage during assembly. The sensor tube 13 can likewise be made of plastic. In this case, it is bonded to or cast with the evaporator tube 4. The sensor tube 14 can however also be made of metal. In this case welding or soldering to the evaporator tube 4 should be preferred.

LIST OF REFERENCE CHARACTERS

1 Inner shell of the refrigeration appliance

2 Insulating foam

3 Wire tubular compressor

4 Compressor tube

5 Transverse wires

6 Holder

7 Groove

8 Protective tube

9 Temperature sensor

10 Contact tongues

11 Sensor support

12 Clamp

13 Sensor tube

14 Insertion funnel 

1-8. (canceled)
 9. A refrigeration appliance comprising: an inner shell delimiting an interior in which at least one of refrigerated products and frozen products can be stored; a control system; a refrigeration unit; a temperature sensor located in the interior, the temperature sensor being connected to the control system; and a screen, the screen preventing contact between the temperature sensor and refrigerated products and frozen products that may be stored in the interior.
 10. The refrigeration appliance as claimed in claim 9, wherein the refrigeration unit is configured as an evaporator.
 11. The refrigeration appliance as claimed in claim 10, wherein the evaporator forms the screen for the temperature sensor.
 12. The refrigeration appliance as claimed in claim 11, wherein the temperature sensor is arranged between the inner shell and the evaporator.
 13. The refrigeration appliance as claimed in claim 12, wherein the temperature sensor is accommodated in a groove on the inside of the inner shell.
 14. The refrigeration appliance as claimed in claim 13, wherein the temperature sensor is arranged in a protective tube.
 15. The refrigeration appliance as claimed in claim 14, wherein the protective tube is permanently connected to the evaporator.
 16. The refrigeration appliance as claimed in claim 15, wherein the protective tube has an insertion funnel for the assembly of the temperature sensor. 